1
L
loop
pol
Ucomp
U
I
Z
=
-
×
EQUATION1793 V1 EN
(Equation 39)
where
U
pol
is the polarizing voltage (memorized UL1 for Phase L1-to- earth fault)
Z
loop
is the loop impedance, which in general terms can be expressed as
(
)
1
1
Z +ZN
1
Z
KN
=
× +
where
Z
1
is the positive sequence impedance of the line (Ohm/phase)
KN
is the zero-sequence compensator factor
The angle β between the Ucomp and the polarize voltage Upol for a L1-to-earth fault
is
β
=
−
+
⋅
(
)
⋅
−
(
)
arg
arg
U
I
K N
ZPE
Upol
L
L
I
1
1
0
3
GUID-A9492CDF-D3B7-4DC5-8E06-6638BEE2540B V2 EN
(Equation 40)
where
U
L1
is the phase voltage in faulty phase L1
I
L1
is the phase current in faulty phase L1
3I
0
is the zero-sequence current in faulty phase L1
KN
Z0-Z1
3 Z1
×
the setting parameter for the zero sequence
compensation consisting of the magnitude
KN and
the angle
KNAng.
U
pol
is the 100% of positive sequence memorized voltage
U
L1
1MRK502052-UEN B
Section 7
Impedance protection
189
Technical manual
Summary of Contents for Relion REG670
Page 1: ...Relion 670 series Generator protection REG670 2 0 IEC Technical manual ...
Page 2: ......
Page 44: ...38 ...
Page 58: ...52 ...
Page 80: ...74 ...
Page 106: ...100 ...
Page 482: ...476 ...
Page 548: ...542 ...
Page 570: ...564 ...
Page 600: ...594 ...
Page 608: ...602 ...
Page 630: ...624 ...
Page 862: ...856 ...
Page 1094: ...1088 ...
Page 1226: ...1220 ...
Page 1250: ...1244 ...
Page 1297: ...1291 ...